Mixing Acetonitrile with Water...What happens???

[archang]

A trivial but thought-provoking question:

Why does a mixture of water and acetonitrile (as well as other organic solvents) become cold?

I have been using HPLC for a while now but only recently noticed this phenomenon...

Any scientific explanations would be appreciated.

Thanks!

[zokitano]

You can find some of the answers you're looking for in the previous thread:
http://www.sepsci.com/chromforum/viewto ... xing+water

Regards